MORGANTON — Twelve activists who blocked a North Carolina chemical plant were arrested in a protest against the company’s sale of products used in the natural gas drilling process called hydraulic fracturing, or fracking.

Morganton Public Safety Chief Mark Tolbert said the protesters faced a variety of charges, including trespassing, resisting arrest and disorderly conduct.

Croatan Earth First! spokeswoman Maria Rowan said sheriff’s deputies and police began warning dozens of activists at the Momentive resin plant on Monday afternoon that they had a half hour to disperse — or risk arrest.

She said the environmental activists, who had been protesting at the plant for hours, were starting to leave when police moved in. “It seemed they were randomly grabbing people as the crowd was actually moving. I’m not sure why,” Rowan added.

Tolbert said protesters ignored the warnings to leave.

“They were interrupting the flow of business for the company,” he said. “The company was already late delivering a load of product to a destination and had not left yet. The company said they had to get the truck on the road. When some of the protesters continued to speak and disrupt the flow of things ... we tried to break it up. But it kind of escalated,” Tolbert said.

“We didn’t want it to go that way and the company didn’t want it to go that way either. We really wanted it just to be peaceful. We wanted it to be like, ‘OK, if you’re not going to leave we’ll just put you in these flex cuffs and take you down and post your bond and go on your way.’ It didn’t exactly go that smooth. But it wasn’t a bad situation, either,” he said.

Between six and 10 police officers and Burke County sheriff’s deputies had been watching the protesters at the plant in Morganton, about 60 miles northwest of Charlotte. Protesters had erected wooden barriers at each of the plant’s two gates before 8 a.m.

The blockade began after the plant’s employees had arrived for work, and production was able to continue during the protest. However, a tanker truck was stopped from leaving to deliver a shipment, Tolbert said.

Protesters erected the pair of three-legged, 20-foot-tall wooden structures at the plant gates. Each has a protester stationed on top, and their safety could be imperiled if they were forcibly removed or the tripod toppled, said Rowan, 44, of Carrboro. As many as 100 other people were lying down in the entrance road, she said.

The group aims to stop the spread of fracking to North Carolina, where lawmakers have created a commission to establish rules that would allow the process to be used to extract gas from underground rock, Rowan said by telephone from the scene.

Supporters say fracking will bring a much-needed economic boost. Some scientists believe some North Carolina counties may hold large deposits of the gas. But fracking opponents are concerned about possible harm to people and the environment.

Columbus, Ohio-based Momentive Specialty Chemicals Inc. was working with law officers “to ensure the safety of all parties,” spokesman John Kompa said in an emailed statement.

“MSC is committed to providing innovative, safe and effective solutions designed to help increase the efficiency of oil and gas operations,” Kompa said. “Hydraulic fracturing has been used by the oil and gas industry since the 1940s and has become a key element of oil and natural gas extraction worldwide. We believe modern hydraulic fracturing is a safe ... and controlled procedure.”

Momentive Specialty Chemicals is owned by parent company Momentive Performance Materials Holdings LLC, which was formed in 2010 with the combination of Momentive Performance Materials Inc. and Hexion Specialty Chemicals Inc. The parent company is controlled by Apollo Global Management LLC, which is known for buying troubled brands and later selling them for a profit. Apollo’s investments include fast-food chains Carl’s Jr. and Hardee’s.